1. Field of the Invention
This invention relates to methods and systems for identification and authentication. More specifically, the invention is a method and system for identifying and authenticating an object using both x-ray fluorescence and visible symbol imaging.
2. Description of the Related Art
Object marking for purpose of object identification comes in a variety of forms. Visible, optically-read marks such as bar codes and data matrix symbols are used in commercial, government, and military applications. Numerous visible-marking and detection systems are known in the art. Invisible markings or “taggants” are used when an object must be covertly marked for later verification or authentication by a specialized detection system. “Invisible” taggants can be realized by, for example, nanoparticles contained in a clear coating or covered by a protective coating. The invisible taggants are trace deposits of one or more elements that are detected and analyzed. For example, the taggants can include elements that fluoresce when exposed to x-rays. The x-ray fluorescent spectrum of the taggant serves as the object identifier. However, even with these known technologies, there is still a need in the art of object marking, identification and authentication for a system/method that allows an object to be readily identified and authenticated at different points in time with a high degree of confidence.